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<h1><a name="SECTION00181100000000000000000">
16.11 <tt class="module">pipes</tt> --
         Interface to shell pipelines</a>
</h1>

<p>
<a name="module-pipes"></a>  
<p class="availability">Availability: <span
 class="platform">Unix</span>.</p>

<p>
The <tt class="module">pipes</tt> module defines a class to abstract the concept of
a <em>pipeline</em> -- a sequence of converters from one file to 
another.

<p>
Because the module uses <b class="program">/bin/sh</b> command lines, a POSIX or
compatible shell for <tt class="function">os.system()</tt> and <tt class="function">os.popen()</tt>
is required.

<p>
The <tt class="module">pipes</tt> module defines the following class:

<p>
<dl><dt><table cellpadding="0" cellspacing="0"><tr valign="baseline">
  <td><nobr><b><span class="typelabel">class</span>&nbsp;<tt id='l2h-3566' xml:id='l2h-3566' class="class">Template</tt></b>(</nobr></td>
  <td><var></var>)</td></tr></table></dt>
<dd>
An abstraction of a pipeline.
</dl>

<p>
Example:

<p>
<div class="verbatim"><pre>
&gt;&gt;&gt; import pipes
&gt;&gt;&gt; t=pipes.Template()
&gt;&gt;&gt; t.append('tr a-z A-Z', '--')
&gt;&gt;&gt; f=t.open('/tmp/1', 'w')
&gt;&gt;&gt; f.write('hello world')
&gt;&gt;&gt; f.close()
&gt;&gt;&gt; open('/tmp/1').read()
'HELLO WORLD'
</pre></div>

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